PTCs have been in use as motor starting switches for many years, where reset time is not a critical factor, for example in refrigeration and air conditioning apparatus. Additionally, motors utilizing a centrifugal start are generally motors which are employed for intermittent, short run applications. Typically, centrifugal switches will energize the start winding until sufficient motor speed is reached causing the centrifugal mechanism to disengage the switch and thereby deenergize the start winding. Although these switches all almost no resistance in series with the start winding, contact arcing (which occurs due to mechanical make and break) can reduce the life of this system. Also, the number and complexity of components means a higher cost associated with such centrifugal starting systems.
While such prior art devices have provided improvement in the area intended, there still exists a great need for a quick or rapid reset motor starting device.
Accordingly, a principal object of the present invention is to provide a quick reset motor starting device.
Another object of the present invention is to provide a PTC reset motor starting device which provides for substantially instantaneous reset design.
A still further object of the present invention is to provide a PTC quick reset motor starting device having an improved heat dissipation feature.
Other objects and advantages of the present invention will in part appear hereinafter and will in part become apparent after consideration of the specification with reference to the accompanying drawings.